diff --git a/packages/core/test/test_bed_spec.ts b/packages/core/test/test_bed_spec.ts
index 5ec2d3f556..6a3eecf927 100644
--- a/packages/core/test/test_bed_spec.ts
+++ b/packages/core/test/test_bed_spec.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {ChangeDetectorRef, Compiler, Component, Directive, ErrorHandler, Inject, Injectable, InjectionToken, Injector, Input, ModuleWithProviders, NgModule, Optional, Pipe, Type, ViewChild, ɵsetClassMetadata as setClassMetadata, ɵɵdefineComponent as defineComponent, ɵɵdefineInjector as defineInjector, ɵɵdefineNgModule as defineNgModule, ɵɵsetNgModuleScope as setNgModuleScope, ɵɵtext as text} from '@angular/core';
+import {APP_INITIALIZER, ChangeDetectorRef, Compiler, Component, Directive, ErrorHandler, Inject, Injectable, InjectionToken, Injector, Input, LOCALE_ID, ModuleWithProviders, NgModule, Optional, Pipe, Type, ViewChild, ɵsetClassMetadata as setClassMetadata, ɵɵdefineComponent as defineComponent, ɵɵdefineInjector as defineInjector, ɵɵdefineNgModule as defineNgModule, ɵɵsetNgModuleScope as setNgModuleScope, ɵɵtext as text} from '@angular/core';
 import {TestBed, getTestBed} from '@angular/core/testing/src/test_bed';
 import {By} from '@angular/platform-browser';
 import {expect} from '@angular/platform-browser/testing/src/matchers';
@@ -245,6 +245,21 @@ describe('TestBed', () => {
     expect(hello.nativeElement).toHaveText('Hello World!');
   });
 
+  it('should run `APP_INITIALIZER` before accessing `LOCALE_ID` provider', () => {
+    let locale: string = '';
+    @NgModule({
+      providers: [
+        {provide: APP_INITIALIZER, useValue: () => locale = 'fr-FR', multi: true},
+        {provide: LOCALE_ID, useFactory: () => locale}
+      ]
+    })
+    class TestModule {
+    }
+
+    TestBed.configureTestingModule({imports: [TestModule]});
+    expect(TestBed.inject(LOCALE_ID)).toBe('fr-FR');
+  });
+
   it('allow to override a provider', () => {
     TestBed.overrideProvider(NAME, {useValue: 'injected World!'});
     const hello = TestBed.createComponent(HelloWorld);
diff --git a/packages/core/testing/src/r3_test_bed_compiler.ts b/packages/core/testing/src/r3_test_bed_compiler.ts
index 5a46e92403..a01aec19cf 100644
--- a/packages/core/testing/src/r3_test_bed_compiler.ts
+++ b/packages/core/testing/src/r3_test_bed_compiler.ts
@@ -257,14 +257,16 @@ export class R3TestBedCompiler {
     const parentInjector = this.platform.injector;
     this.testModuleRef = new NgModuleRef(this.testModuleType, parentInjector);
 
-    // Set the locale ID, it can be overridden for the tests
-    const localeId = this.testModuleRef.injector.get(LOCALE_ID, DEFAULT_LOCALE_ID);
-    setLocaleId(localeId);
-
     // ApplicationInitStatus.runInitializers() is marked @internal to core.
     // Cast it to any before accessing it.
     (this.testModuleRef.injector.get(ApplicationInitStatus) as any).runInitializers();
 
+    // Set locale ID after running app initializers, since locale information might be updated while
+    // running initializers. This is also consistent with the execution order while bootstrapping an
+    // app (see `packages/core/src/application_ref.ts` file).
+    const localeId = this.testModuleRef.injector.get(LOCALE_ID, DEFAULT_LOCALE_ID);
+    setLocaleId(localeId);
+
     return this.testModuleRef;
   }